I had a book when I was a kid called The Little Fish that Got Away. I could write a book for my clients about The Little Invention that Got Away!
Many people have a lot of great ideas. Yet many of those great ideas have been had before-and patented. Just yesterday I was working on a case for a client where we thought we had a new idea and that we'd better rush to get the patent application written and filed. My client knew the market well and hadn't seen this idea for a product feature anywhere else. Yet, just as a precaution, I did a search of The United States Patent and Trademark Office Patent database as I was starting in on the application. Good thing I did. I came up with some references (old patents) which seem to disclose my client's invention.
I can't tell you how many times this has happened. Yet one shouldn't be so disappointed. After all, it shows your invention was patentable-just someone else beat you to it -The invention that got away!